Carburetor economizer mechanism



Feb. 3, 1953 Hl 2,627,279

CARBURETOR ECONOMIZER MECHANISM Filed June 21, 1949 INVENTOR. R0552? hfH/EGEE A77 E K Patented Feb. 3, 1953 -UNIT E D PATENT OFFICE "2,627,279oABEoREToRiiooNomzER MECHANISM Robert HJH'ie er, Detroit, Mich.apti'ieationirune zi, 1949, serai-Naiooe'as *s Claims. (01. I 137-480)This invention relates to carburetorssfor intirlal Combustione'il'giIl'eS, and md'reIhrtibularlyto an eeonomizer mechanism "to enablethe carburetor to sup'piyiuei "to the engine increased quantity "toincrease "are "power thereof Whenne'eded. I 7

Many commercial carburetors as now constructed include a device, usuallyYeferie'dto as an 'ecdh'oinizer orpower jet, which includes 'a Valvecontrolled by ii/piston or diaphragm subjectedto the vacuum inthe intakemanifold to increase the rate of fue'lsupplied to 'theca'r'buretor, andthereby enrich the fuel-air mixture,

When thethrottle isin ornear its fully open position.

In the case an economizer "comprising afvac- "actuated piston, defectiveoperation or failure of the economizer often results from co'r- 'ro'sionof'the cylinder walls, which develops-friction and causes'the'economize'r jto'oper'ate haphazardly or'not at all. Such 'friction'mayalso be caused by misalignment of the piston in its cylinder, by grit orother foreign matter therein, or' byother causes.

Defective operation of the economizer may also'result from the returnspring commonly used in such devices, and'whi'oh may have too "great ortoo small initial tension, causing the-economizer to begin to funotiontoo soon, or too late, relative to a given decrease of vacuum in themanifold. i

Defective operation of the economizer is difficult to detect, sincecommercial carburetorsare so constructed that iti's impossible,withoutidis assembling the carburetor, to applya measured "amount ofsuction to the fuel outlet thereof and to the vacuum connection, andmeasure the resulting fuel flow. Also, if malfunctioning is found orsuspected, it is diflieult to reme'zdy 'by means of ordinaryshop tools.

An object of the present invention is to provide "a earburetorcomprising econbmizermeohanism having improved eontrol or motor meanswhich are not prone to get out of orderfand wherein corrosion and alsomisalignment between the piston and its cylinder areavoid'ed.

A further object of the invention is to provide "an economizer motorwhich is usable in known types of carburetors in substitution for thecorresponding mechanism originally supplied with the carburetor.

In the device of the present invention, the economizer motor unitcomprises a piston and a cylinder of corrosion-resistant material such,as brass, which may be substitutedfor the corresponding elements in anew or used carburetor. A piston rod is connected to the piston by auniversal connection, so that the piston rod, which actuates theeconomizer valve, cannot cause misalignment "of the p'i's'ton relativeto its cylinder. v

Further objects and advantages or the inventionwill be apparent fromthefollovving lie e p tionftaken in 'connec'tibh with the a pntiddrawing i'n which: V v

Fig.1 is adiagr aininat'ic view of aearbfure'tor and theful'systinthereof'showing, on a fenlarged scale, a device With'the'piesent iril'ntion incorporated therein. V

Fig. 2 isfan enlar ed sectional View df'the economizer motor and itsassociated parts, corresponding to "a seetion taken on the line "-220I"Fig. 1. s I v Fig. 3 is an enlarged plan View of one of the washersshown i'n'Fig.'l. V

Fig.4 is an elevjatienal tietv showingth'e economizer rn'otorseparately, fife. in the forin it is distributed tofithe trade as aseparate article of manufacture for installatibn in "the earbiireto'rsofcars already on theroad.

.It is to beunderstoo'd thattneiiiventioi is "not limited in itsapplication tothe details "ojf'con- "struction and arrangement ofpartsjllustrated in "the accompanying drawing, since the inventioniscapab1e or otherenibodimentsandf ofbeing practiced or car'i ied out invarious Also it is to be understood that the biirasebiogy or terminologyemployed herein is for'fthe purpo'seof description a'nd not oflimitation.

The Tcarbu'ret'or 'si ownfii ithe drawiiigl sjqrthe downdraft type"commonly used with automobile engines, but may "be "off any know orsuitable construction. It comprise's 'a body 8 forming an inductionpassage which includes an air inlet II], a main venturi l2, anda mixtureoutlet, 14 designed to be con ected to the intake manifold of aninternal combustion engine, not shown. The induction passage 'isjcontrolled in the usual manner by a manually orieratd'tlirottl'e valve:6. Usually an "air cleaner, such .as is indicated fragmentarily at 1 8,is connected to the air inlet.

Fuel is supplied to t eiinauet pn .bassage from a reservoir 20, which'inthe examine shown isia float chamber h ving a float 22 therein. W hioh'actuates a fuel valve tontroiiing a fuel iill lt jz s leading from anysuitable so me Lof supply.

throttle is wh' 'if the same "is in closed bosition;

Suitable acceleration pump mechanism, as well as check valves, vents andmetering orifices may be provided, as known in the art.

The motor or control unit of the economizer comprises a cylinder 38connected by a duct 49 to the induction passage of the carburetorposterior to the throttle l6 when the same i in closed position. Apiston 42 in the cylinder is thus subjected to the manifold vacuum,which tends to move it upwardly. A piston rod 44 is carried by thepiston 42 and extends downwardly therefrom, terminating in a shoe 46which acts as a seat for a compression spring 48 which yieldingly urgesthe shoe downwardly against the force of the manifold vacuum. Thearrangement thus far described is broadly old, but some of the elementsthus far mentioned have novel features, as will appear hereinafter.

The valve unit of the economizer comprises a casing 54 mounted in thelower wall of the float chamber, and housing a spring-pressed valvemember 52 which controls the flow of auxiliary fuel from the floatchamber 20 through a restricted passage 54. to the fuel passage 28.Projecting upwardly from the valve 52 is a plunger 56 which is designedto be depressed by the shoe 44 when the piston 42 moves downwardly. Thisvalve unit may be of known construction, an example being the'unit'shownin applicants copending application Serial No. 83,687, filed March 26,1949.

As indicated in Fig. 2, the cylinder 38 is formed in a portion 53 of thecarburetor body which overlies the float chamber 20 and is usuallyformed integral with the air horn of the carburetor. Since thecarburetor body is usually made of a zinc alloy which is subject toattack by various ingredients of commercial gasoline, the walls of thecylinder sometimes become corroded, causing the vacuum piston to freezeor otherwise misfunction. To avoid this, the cylinder, in the presentinvention, is provided with a cylindrical liner 64, of brass or similarnon-corrodible material, and of such diameter as to receive the piston42 in freely slidable relation.

A plug 62 is driven into th lower end'of the liner sleeve 50, the plugbeing formed with a bore 63 to loosely receive the piston rod 44. Theplug is provided with a flange 64 which may be tapered to insure a tightfit in the bore of the liner sleeve, and with a depending flange 66which receives the upper end of spring 48.

The upper end of rod 44 is threaded, and engages the threaded bore of a,sleeve nut H! which seats loosely in a bore 12 in the upper end ofpiston 42. The bore 12 is connected to a smaller bore 14 in the piston42 by a shoulder 16. Between the nut 14 and the shoulder 16 ispositioned an annular resilient sealing member 18, of Buna N or thelike, such as is disclosed in applicants copending application SerialNo. 83,688, died March 26, 1949. Because the pring 48 exerts a constantdownward force on the piston 42, the sealing member 78 is continuouslyunder pressure, so that it is distorted in such manner as to provide anair tight seal against passage of air between bore 14 and bore 12, eventhough the nut 10 rocks relative to piston 42 as hereinafter mentioned.The piston 42 may be provided with a peripheral groove 80, as is usual.

The piston 42 is provided with a depending annular flange 82 designed tocontact the beveled upper edge of flange 64 when the piston is moved toits lowermost position by spring 48. In order to make it possible tovary the initial tension of spring 48, a plurality of U-washers 84 arein sorted between the plug 62 and the upper end of the spring, and heldin place by the flange 66. The U-washers may be removed, or more of themadded, by depressing the upper end of the spring to a point below theflange 66.

Under certain conditions such as sudden deceleration of the vehicle onwhich the carburetor is mounted, liquid fuel may be splashed over theeconomizer motor unit in such a way as to fill the space 86 between thepiston 42 and the plug 62, and a quantity of such fuel may, unlessprevented by means now to be described, be drawn by suction through theclearance space between sleeve 60 and piston 42 and thence through duct49 to the engine, which will thus be caused to misfire. In the presentdevice, this is prevented by venting the space 86 so that substantiallyatmospheric pressure will at all times obtain therein. To this end, aduct 88 leads from the air inlet lfl to a cylindrical chamber 90 formedby reducing the outer diameter of sleeve 60 as indicated in Fig. 2.Thence the duct communicates with space 86 through a port 92 in thesleeve. This port is shown in Fig. 2 as being aligned with duct 34, butobviously no such alignment is necessary. By reason of thisconstruction, any fuel which may be present in space 86 is free to flowdownwardly through bore 63 to the float chamber, and little be drawnthrough duct 40.

In the assembly of the parts making up the vacuum motor, spring 48 andplug 62 are placed on the piston rod 44, with any desired number ofwashers 84 interposed therebetween. The piston 42, and then the sealingmember 18, are then placed on the rod, the piston being held downagainst the resistance of spring 48 in order to permit the sealingmember to be properly positioned. The nut H3 is then threaded into placeon the rod 44 and the piston released, putting the sealing member underpressure. The sleeve liner 68 is then driven into engagement with theplug 62. This assembly of parts may then be tested by the use of simpletest equipment (not shown) to determine whether it functions properlyunder a given degree of manifold vacuum, and such adjustment as may benecessary is made by varying the number of washers 84. The cylinder 38is then cleared of any foreign matter or irregularities, and theassembly is driven into place in the cylinder, plug 62 being staked ifdesired to retain it in position.

In general, the fuel system of the carburetor just described functionsin the same manner as the fuel systems in known types of carburetors.During normal operation of the carburetor the manifold vacuum issufficiently high to hold piston 42 in its raised position, as shown inthe drawing, so that valve 52 is closed and the entire supply of fuel tothe nozzle 52 passes through metering orifice 36. But when the manifoldvacuum drops, as when the throttle I6 is suddenly opened, spring 48 willmove rod 44 downwardly to a position wherein the shoe 46 contacts theplunger 55, which will move the valve 52 oii its seat and permitauxiliary fuel to flow from float chamber 20 past valve 52 and thencethrough passage 54 to the nozzle 32, enriching the mixture.

The ec'onomizer mechanism herein disclosed is resistant to corrosion,since all of its parts which are subject to sticking are formed of brassor other material not subject to corrosion, and clearances aresufificient to minimize the danger of such occurrence. In addition, suchclearance is provided between nut 42 and bore 12, and between rod M andbores 14 and 63, as to permit the nut '10 to tilt or rock slightlyrelative to the piston, and sealing member 18 by reason of itsresilience permits such action while still maintaining its sealingaction. The connection between rod 44 and piston 42 is a universalconnection, and any misalignment between the rod and the sleeve 00 isthus automatically adjusted. If at any time there is a question whetherthe unit is functioning properly, or if it is desired to test thefunctioning of the motor, the entire motor unit may be removed from thecarburetor. A measured degree of manifold vacuum may then be applied tothe piston 42 to test the action thereof in moving rod 44. If the unitis found not to be functioning properly, the defective parts may beadjusted or replaced, and the unit re placed without disturbing itsadjustment.

Although the invention has been described with reference to a particularembodiment thereof, it may be embodied in other forms within the skillof artisans in this art, and is not limited except in accordance withthe terms of the following claims.

I claim:

1. A unit for actuating economizer valve of a carburetor having an airpassage with a throttle provided therein and a float chamber andincluding a cylindrical bore at the top of said chamber, said boreopening into said chamber with its lower end, the upper end of said boreconstantly communicating with said air passage on the downstream side ofthe throttle; said unit comprising a sleeve adapted to fit into saidbore and to form a liner therein, a piston slidably fitted in saidsleeve and having a through axial bore of different diameters to form ashoulder therein adapted to receive downward pressure, a piston rodhaving its upp r end passing through said bore and engaging saidshoulder for moving the piston downwardly and its lower end adapted tocontact the economizer valve, and a plug surrounding the piston rod andsecured to the lower end of said sleeve and adapted to be secured at thelower end of the sleeve-receiving bore for retaining the sleeve therein,said sleeve retainin in place, in the assembled condition of the unit,the piston, the plug and. the piston rod.

2. The construction defined in claim 1, with a compression springinterposed between the lower end of the piston rod and the plug andadapted to maintain said rod, unless overcome by an exterior force, inits fully extended position; and a washer box on said plug adapted toreceive a desired number of spring-adjusting washers.

3. A unit for actuating economizer valve of a carburetor having an airpassage with a throttle provided therein and a fioat chamber andincluding a cylindrical bore at the top of said chamber, said boreopening into said chamber withits lower end, the upper end of said boreconstantly communicating with said air passage on the downstream side ofthe throttle; said unit comprising a sleeve adapted to fit into saidbore and to form a liner therein, a piston slidably fitted in saidsleeve and having a through axial bore of at least two diameters to forma shoulder therein, a piston rod having its upper end passing throughsaid bore and engaging said shoulder for moving the piston downwardlyand its lower end adapted to contact the economizer valve, a sealingmember interposed between the upper end of the piston rod and saidshoulder and adapted, when the piston rod exerts pressure on saidshoulder, to seal the axial bore in said piston to flow of fluid.

4. A unit for actuating economizer valve of a carburetor having an airpassage with a throttle provided therein and a float chamber andincluding a cylindrical bore at the top of said chamber, said boreopening into said chamber with its lower end, the upper end of said boreconstantly communicating with said air passage on the downstream side ofthe throttle; said unit comprising a sleeve adapted to fit into saidbore and to form a liner therein, a piston slidably fitted in saidsleeve, and having a through axial bore of two diameters to form ashoulder therein, a piston rod having its upper end passing through saidbore and engaging said shoulder for moving the piston downwardly and itslower end adapted to contact the economizer valve, a sealing memberinterposed between the upper end of the piston rod and said shoulder andadapted, when the piston rod exerts pressure on said shoulder, to sealthe axial bore in said piston to flow of fluid, saidl piston rod havingdiameter efiecting predetermined clearance between the rod and thepiston as well as the plug, providing for such sidewise movement of therod in the sleeve as may be caused in operation by the angularmisalignment of the rod.

5. A unit for actuating economizer valve of a carburetor having an airpassage with a throttle provided therein and a float chamber andincluding a cylindrical bore at the top of said chamber, said boreopening into said chamber with its lower end, the upper end of said boreconstantly communicating with said air passage on the downstream side ofthe throttle; said unit including a piston adapted to operate withinsaid bore, said piston having a through axial bore of differentdiameters to form a shoulder therein adapted to received downwardpressure, a piston rod having one end arranged within the bore of thepiston with a predetermined clearance and extending beyond saidshoulder, a member provided on the end of said piston rod and adapted,when a downward force is exerted on the rod, to exert pressure on saidshoulder, and a sealing member interposed between said member and saidshoulder and adapted to seal said clearance when the piston rod exertthrough its end member pressure toward said shoulder.

6. The construction defined in claim 5, with said sealing member beingmade of a material having elasticity ensuring that the member on the endof the piston rod exerts sealing pressure on the entire sealing membereven when the piston rod is in the position of the maximum axialmisalignment determined by the clearance.

ROBERT H. HIEGER.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 2,015,709 Chandler Oct. 1, 19352,038,206 Chandler Apr. 21, 1936 2,045,196 Mohr June 23, 1936 2,094,569Dwyer Sept. 28, 1937 2,157,005 Nylander H.-- May 2, 1939 2,312,817Heftler Mar. 2,. 1943 FOREIGN PATENTS Number Country Date 362,434 GreatBritain Dec. 3, 1931 288,080 England Apr. 5,. 1928

